351w or 347 stroker? which is better?

[WADS56]

Originally posted by tireburner163
I dissagree. The rod/stroke ratio on a 347 far worse than the 351W. The 347 will be using oil WAY before the 351W. Which is why I say.....If you want the motor you last more that 50K miles, go with the 351W.

That is not true. This is a MYTH that just won't die. Machine work will make or brake any engines life. All this "rod to stroke ratio, and oil ring thing" was a false statement so people would buy the 331 strokers from the selected few that offered them when the first came out. They made a killing off this, and now the myth has been spread all over the internet and people buying in to it.

[Mustang_289]

WADS56 - I see from your sig you've got a 347, how many miles on it? Are you saying the 347 is realiable and won't use oil with miles on the block?

All these posts are good info for my son and I as long-term we've got plans for a new motor in our stang. We've looking at everything from a 306 up to a punched out 351.

[WADS56]

I am saying that a motor is only as good as the parts and the machine work that go's in to it. I myself don't know how many miles are on it because I don't have a odomoter. I can tell you that i have beat the crap out of it for two seasons now and it has no oil issues or anything. In fact it is tore down now and you can still see all the honeing in the cylinders. If 347's have a bad rod ratio I would see ware in the cylinders by now from the piston side loading on the wall. A good rule of thumb is... If it is a oil burner from break in it will be a oil burner all its life.

[Ron1]

Have to agree with WADS56. I keep hearing this "oh, I heard this about the 347"...that it burns oil, and has a "bad rod ratio". Same rod ratio as a chevy 350, and they built millions of those. I have yet to have anyone give me first hand knowledge of these "bad" 347's". Coast and FPS now have pistons with the pins removed from the ring land area. So far I am happy with my 347, 98 % drag race application, but no probems yet and great power.

Ron

[Smokedawg]

I had no oil probs with my 347 when it was running...Just tore it down to upgrade some parts(heads, intake, cam..etc) and having a hard time getting things back to normal...

[tireburner163]

"The primary reason for longevity issues was the oil ring in the wrist pin area. That problem has been addressed by several manufacturers. But, they still push the rings too close to the wrist pin, and have a rod/stroke ratio a little on the nasty side from my understanding The extra cubes you get going to a 347 from a 331 are minor, and not worth the possible reprocussions in my opinion"

[bottlebaby91]

RON1: The reason a 350 chevy has no problems with the same rod ratio is beacuse of the taller deck height.

Personally, if i was to stroke a 302 the max I would go is a 331. Been than again i am running a 306 and run circles around most 347's. I have seen a 306 make well over 600 n/a rwhp and have seen 306's into the 8 sec range. They say there is no replacement for displacement .........N2O......the displacement replacement....

just my 2cents

[WADS56]

331's have the oil ring in the ristpin area as well. And yes the rings are a little tighter on the 347 but that is not a issue. The only advantage that a 331 has over the 347 is in a power adder app. There is some more meat on top of the piston on a 331 to handle the abuse a little better.

And yes nitrous is a replacement, but i can put nitrous on my lawnmower.

[Eric4Nitrous]

but i can put nitrous on my lawnmower

sure, but you don't know how to tune it.

[sn95gt19]

so your saying that i might have a little problem with a 300hp fogger kit, w/347 5.4 rod 8.5:1 combo?? i have the pms and it should be tuned perfect, do you think ill have a piston problem.

btw:i have je/srp 8.5:1 pistons

[WADS56]

Originally posted by sn95gt19
so your saying that i might have a little problem with a 300hp fogger kit, w/347 5.4 rod 8.5:1 combo?? i have the pms and it should be tuned perfect, do you think ill have a piston problem.

btw:i have je/srp 8.5:1 pistons

Are you using the turbo, or nitrous? 8:5 is a very low compression ratio for a nitrous motor it is perfect for that turbo though. Anyways... if you are spraying a 300 shot on your 347 with the stock block your pistons should be fine untill they get blown through the oil pan

[sn95gt19]

yeah i found another turbo to get but i dont think i can afford it until next year so i figured just spray it 300 until i can afford the turbo. you guys think it'll run pretty good with 8.5:1 w/300 shot? or do you have something else that i can do in the meantime.

any suggestions??????????

hopefully the crank/block will hold up with my abuse

[Eric4Nitrous]

it would run better with more compression. If your motor can handle it...sure go for it.

[sn95gt19]

i have a main support, eagle forged crank(4340), eagle h beam rods(4340) and je/srp 8.5:1 pistons(forged) with that low of compression do you think it would be able to hold up with a 300shot.

with it being perfectly tuned with race gas???

just need some opinions thanks

[greydan]

Don't you loose engine life , because of a shorter piston skirt with a stroker in the 302>347? My understanding was a 302 stroker piston had less of a skirt.




Oh.. Clawson Michigan is just north of DEtroit...

[2FastLX]

Originally posted by WADS56
...I can tell you that i have beat the crap out of it for two seasons now and it has no oil issues or anything. In fact it is tore down now and you can still see all the honeing in the cylinders. If 347's have a bad rod ratio I would see ware in the cylinders by now from the piston side loading on the wall. A good rule of thumb is... If it is a oil burner from break in it will be a oil burner all its life.

I gotta back my buddy Wade here...
I can honestly tell you for a fact I have seen Wade beating the crap out of his 347. This guy leaves the line like a raging Pitbull on Steroids. I've seen him break everything from axles to crossmembers. And he knows his poo. I am a firm believer that if a 347 can hold up to the kind of abuse this guy dishes out you have absolutely nothing to worry about. Just look at his parts list, copy the build, and find a good engine builder. It'll last forever on the street

Another issue I haven't seen anyone bring up (or I missed it) is the fact that the 351W block weighs something like 50lbs heavier than a 5.0 block (correct me if I'm wrong please). I'm not up on how much horsepower 50lbs of weight added to your car is comparable to, but you get the idea.

[WADS56]

Thanks for the kind words <(insert embarassed face here). Also, thanks for reminding me about all the money I spent on replacing broken parts I was trying to forget about that


Good advice though. "Find a good engine builder and it will last a long time"

[sn95gt19]

i mean w/ 300shot, im sure it'll last a long time n/a but i dont think thats going to be enough for me. what do you think the longevity of a 347 w/300 hp fogger kit would be?

[HORSEMEN RACING]

if there is concern about the "so called" oil ring problems just get the 347 kit with the 5.315 rods and that will alleviate that problem.

[ultraflo]

Originally posted by sn95gt19
i mean w/ 300shot, im sure it'll last a long time n/a but i dont think thats going to be enough for me. what do you think the longevity of a 347 w/300 hp fogger kit would be?

I haven't followed the entire post... what block are you using?

A stock block will not reliably hold a 300shot... I had just over 60 passes with a 200shot on a stock block 306 combo before the block split. A B50 block w/ a girdle would maybe do a better job, but still is pushing the limits, and wouldn't last a long, happy life.

The ONLY way you're going to put 300hp of nitrous to a 400hp+ n/a 347 is to go with an R-block or Dart block.

And, yes, I also agree with Wade and 2Fast that the 347 is a more desireable combo over the 351... all things being equal, of course. Now if you stroke the 351 it's a whole new ballgame.